Abstract

The efficiency of extracting 2-(thiocyanomethylthio) benzothiazole (TCMTB) with dichloromethane from treated wet blue samples was investigated and the high-performance liquid chromatography (HPLC) method of determining the extracted TCMTB is described. Of the methods investigated, the most efficient procedure for TCMTB extraction was found to be sonication in boiling dichloromethane for 30 mm followed by a 75 h Soxhlet extraction. Using this method, TCMTB was extracted from wet blue treated at various concentration levels and containing different moisture contents. The amount of TCMTB increased with the amount offered during treatment, although not linearly. The amount extracted increased when the moisture content was lowered by sammying. The actual efficiency of the extraction method was determined in a mass balance experiment in which all masses and volumes were carefully monitored. The average extraction efficiency in treatments up to 0.25% (m/m) fungicide offered in a 100% float was 82% of the total wet blue TCMTB content. An attempt was made to determine the ratio between the interstitial and the bound TCMTB which could have a bearing on the activity of the fungicide. After 30 days, less than 10% of the TCMTB was present in the interstitial fluid.